1. Field of the Invention
Exemplary embodiments of the present general inventive concept relate to an image forming apparatus having a transfer device to transfer an image to a printing medium.
2. Description of the Related Art
Image forming apparatuses are devised to form an image on a printing medium. Examples of image forming apparatuses include printers, copiers, fax machines, and devices combining functions thereof.
In an electro-photographic image forming apparatus as a kind of image forming apparatuses, light is irradiated to a photosensitive member charged with a predetermined electric potential, to form an electrostatic latent image on a surface of the photosensitive member, and a developer is fed to the electrostatic latent image, forming a visible image. The visible image, formed on the photosensitive member, is transferred to a printing medium via a transfer device. After the image transferred to the printing medium undergoes a fusing operation, the printing medium is discharged out of the image forming apparatus.
In the case of a color image forming apparatus, a transfer device generally includes a transfer belt. The color image forming apparatus may realize an image of a desired color by overlapping a plurality of colors of developers on a transfer belt, or may realize an image of a desired color by directly overlapping images on a printing medium fed by the transfer belt.
To allow the color image forming apparatus to print a high quality color image, it may be necessary to appropriately adjust an image density and to accurately align images to be overlapped by the transfer device. To this end, the color image forming apparatus may function to sense a predetermined mark in a sensing region on the transfer belt, appropriately controlling a printing operation according to the sensed result.